James w



(No Model.)

-J. BONTA.

TELEPHONIG TRANSMITTER.- No. 365,780. .PatentedJuly 5; 1887.

V, a a, l

I L a Li M WITNESSES." [NI/570R UNITED STATES JAMES IV. BONTA, OF PHILADELPHIA PATENT OFFICE.

, PENNSYLVANIA, ASSIGNOR TO THE TELEPHONIC TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 365,780, dated July 5, 1887.

Application filed December-2|, 1886 To all whom it may concern.-

Be it known that I, JAMES W. BONTA, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Telephonic Transmitters, of which the following is a specification, reference being had therein to the accompanying drawings, wherein Figure 1 is avertical section of a telephonic transmitter embodying my improvements, and Fig. 2 is a section on line 1 1, Fig. 1.

My invention has relation to telephonic transmitters, and it has for its object simplicity and economy of construction.

My invention consists of the combination, construction, and arrangement of parts, as hereinafter described and claimed, having reference particularly to an electrode having a roller'support and a spring and tension device for varying the contact-pressure between the electrodes.

In the drawings, A represents a suitable box or casing, having a removable cap, a, which is provided with a mouth-piece, a, and diaphragm B, which, as shown, may be a plate of carbon hinged to the diaphragm; orit may be fixed or otherwise arranged as desired.

0 represents a pencil of carbon or other Serial No. 221183. (No model.)

suitablematerial,having,preferably,arounded o front end, 0, for contact with the diaphragm B or an electrode thereon. The forward end of electrode 0 rests upon a-grooved or other roller or anti-friction pulley, D, (see Fig. 2,) suitablyjournaled or supported in casing A. 5 The electrode 0 is connected at its rear end to a plate or bar spring, E, secured to casing A, and is provided with a tension-screw, e, the tendency of which spring is to move the elec trode into contact with the diaphragm. The 0 degree of pressure for such contact is regulated by adjusting screw 0.

The electrodes are in the primary 1 of inductorium 2, which primary includes a battery, 3, and the secondary 4 of the inductorium is a part of the line.

What I claim is In a telephonic transmitter, the combination of diaphragm B and electrode 0, having nearits front end a supporting-roller, D, and 50 its rear end attached to a spring, E, having tension-screw e, substantially as set forth.

In testimony whereof I affix mysignature in presence of two witnesses.

J AMES BONTA.

Witnesses:

S. J. VAN STAVOREN, J. DANIEL EBY. 

